Servo motor angle and direction control with

[ayazahmed]

Friends i m working on a project in which i need to control servo motor with PIC16F877A. I know that sevo motor has 3 pin in which 2 pins are vcc,gnd and 3rd is control pin. We have to give PWM pulse to servo every 20ms to maintain an angle. The duty cycle determines the which angle position to maintain. But the problem is, i have read on internet that we can control 0 to 180 degrees angle position. I want to know how to control other angle positions? Can u suggest any solutions? Please help

 

[cubanflyer]

I assume that you are talking about a great range of angle position. You will find the servo will normally have a mechanical stop to prevent it going too far in either direction, this is usually about 180 degrees. People have taken the mechnical stops out of the servo to allow for greater rotation, but I have not tried this. Normal control of the servos is via PPM (Pulse position modulation) with the pulse width being between 1 and 2 ms.

 

[ayazahmed]

Dear Frndz can any1 give me some ideas about how 2 rotate servo with some defined speed? I know how to control the angle of servo. My servo's range is 180 degrees not 360 degrees. Any help will b appreciated...

 

[ayazahmed]

No Reply .......

 

[bigdogguru]

Servos are commonly limited to 180 degrees rotation, however your correct some are designed to rotate 360 degrees plus. If they are modify, to allow additional rotation, you typically lose the ability to control positon as shown in ACTUATORS - HOW TO MODIFY A SERVO tutorial. The same site also has a very good introductory tutorial ACTUATORS - SERVOS. Controlling a servo which has a greater range of motion than 180 degrees is basicly no different than a 180 model, full rotaion is acheived with by applying PWM at the unit specified duty cycle for full rotation.

Here are several examples of controlling a servo with a PIC.

Basic Servo Motor Controlling with Microchip PIC Microcontroller


Servo Motor Control


**broken link removed**

I hope this info help you in your endeavors